Adjusting devices of the above mentioned kind are already known in many different designs. They may be provided as conventional rotary switches, which allow a stepwise or continuous adjustment of parameters. However, due to the rotary axis required for turning the switch, the bearing of the rotary axis, and, if necessary, the sealing of the rotary axis, such rotary switches are quite expensive in view of production and installation.
Moreover, adjusting devices may comprise one or more touch sensitive sensors, e.g. capacitive sensors, which are coupled to a processing unit for processing the output signals of the sensors. The processing unit is designed in such a manner, that an adjustment or a selection of one or more parameters is realized by touching a sensor one or several times with the finger. According to DE 103 13 401 A1, such touch sensitive sensors can also be arranged in a common plane and extend in an endless row. In this case, the processing unit is designed in such a manner that an adjustment or a selection of parameters is realized by touching or running one's fingers over at least two sensors in sequence. Touch sensitive sensors have the advantage that a rotary axis is not necessary. Accordingly, the production and installation costs can be reduced compared to the ones of rotary switches.
However, when adjusting devices with touch sensitive sensors, in particular an adjusting device of the kind described in DE 103 13 401 A1, are used for an appliance having a small installation height, such as conventional cookers, ovens, dishwashers or washing machines, the sensors should not be arranged on a vertical plane, e.g. on a vertically extending control panel, because a user would have to stoop down in order to operate the device, which is rather unconfortable. Accordingly, the sensors are normally placed on a horizontal plane, e.g. on a Ceran-cooktop, on a control panel provided on the upper side of the appliance or the like. However, if the sensors are arranged on a Ceran-cooktop, they take away space needed for the cooking fields of the Ceran-cooktop. Moreover, washing machines, dishwashers and similar appliances are often integrated in kitchenettes, closets, etc., so that the upper side of the appliance and hence the sensors are not accessible by a user.
Starting from the above-mentioned prior art, it is an object of the present invention to provide an adjusting device for adjusting and/or selecting one or more parameters of an appliance, which is inexpensive to manufacture and to assemble and which is comfortable to handle when it is installed on a vertical plane, such as on a vertical extending control panel.